Cycles material for VR + photo-realism
Cycles and Unity render method are totally different, you can't expect a Cycles material to look the same in Unity. But you can try a few things.

Baking

Baking is a tool that allows to "convert" your material into a texture.  Doc

The advantage is that the (costly) render is done only once, and the realtime engine only have to display a texture (cheap).

The disadvantage is that most material effects can't really be baked, because they are view dependent (ie. reflections).

Lighting can be baked if you don't need dynamic lighting (ie a light that move or change intensity). You can do it with Cycles, but it's certainly easier to do it in Unity Doc

PBR workflow

Physically Based Rendering (PBR) is a workflow that is supported by either Cycles (with the Principled shader) and Unity (with the Standard shader), and many modern game engine. It won't make the Unity shader look better (it's already the default shader), but at least it allow to have a relatively similar result while you are working on your object in Blender.

Game engine side

I won't be really specific cause I'm not an expert (and that's not the place), but a lot of things can be done to boost up a Unity (or UE4) render.
I mentioned light baking. You can also use reflection probes or even Screen Space Reflection to get better looking reflections. Ambient occlusion is a great way to increase realism.